The origin of the isolated population of the Faroe Islands investigated using Y chromosomal markers

Abstract

Historical, archaeological and linguistic sources suggest that the ancestors of the present day population in the Faroe Islands may have their origin in several different regions surrounding the North Atlantic Ocean. In this study we use binary and microsatellite markers of the Y chromosome to analyse genetic diversity in the Faroese population and to compare this with the distribution of genotypes in the putative ancestral populations. Using a combination of genetic distance measures, assignment and phylogenetic analyses, we find a high degree of similarity between the Faroese Y chromosomes and the Norwegian, Swedish and Icelandic Y chromosomes but also some similarity with the Scottish and Irish Y chromosomes. Diversity measures and estimates of effective population sizes also suggest that the original gene pool of the settlers have been influenced by random genetic drift, thus complicating direct comparisons with other populations. No extensive immigration from Iceland to the Faroe Islands can be documented in the historical record. We therefore hypothesise that the high degree of Y chromosome similarity between the two populations arose because they were colonised at approximately the same time by males originating from the same regions of Scandinavia and, to a lesser extent, from the British Isles.

Genetic evidence for a family-based Scandinavian settlement of Shetland and Orkney during the Viking periods

“…While it is possible that genetic drift has affected gene frequencies so that our estimates of admixture no longer accurately reflect the composition of founder populations, it seems unlikely to be coincidental that the overall proportion of Scandinavian ancestry for these three locations decreases in harmony with geographic distance from Scandinavia. Admixture analysis (using mr) of recently published Y-chromosome data from the Faroe Islands (Jorgensen et al, 2004) also provides evidence for a trend of increased Scandinavian patrilineal ancestry in regions further from the British Isles. The estimated Scandinavian genetic component of the Faroese samples is 87% (N ¼ 89, k ¼ 26), a higher figure than for either Shetland or Orkney.…”

Polymorphism of CYP2D6, CYP2C19, CYP2C9 and CYP2C8 in the Faroese population

“…However, an influx of men and women from the British Isles, either as independent colonisers, or brought there by Vikings, may have contributed significantly to the current gene pool of the Faroese population [15]. It has been suggested that the Faroes were populated by Irish monks or hermits as early as 650 A.D. and they may have left before the Norse settlement [16].…”

A genome-wide search for alleles and haplotypes associated with autism and related pervasive developmental disorders on the Faroe Islands

“…Based on historical records the establishment of the population was presumably caused by emigration mainly from Bergen and the surrounding area in Norway approximately 900 AD, but people from the British Isles may also have contributed to the colonization of the islands. 18 Based on a genetic study of paternally inherited Y-chromosomes from the Faroese population, it is likely that the Faroe Islands were colonized by males from Norway, Sweden, and Scotland. 18 The population has expanded from a few thousand people to the present level of approximately 45 000 inhabitants, covering periods of constant population size as well as putative periods of population bottlenecks with less than 4000 inhabitants due to severe epidemics.…”

“…18 Based on a genetic study of paternally inherited Y-chromosomes from the Faroese population, it is likely that the Faroe Islands were colonized by males from Norway, Sweden, and Scotland. 18 The population has expanded from a few thousand people to the present level of approximately 45 000 inhabitants, covering periods of constant population size as well as putative periods of population bottlenecks with less than 4000 inhabitants due to severe epidemics. 19 Migration has been sparse, 18 and presumably the expansion has mainly been due to increased reproduction rates.…”

“…18 The population has expanded from a few thousand people to the present level of approximately 45 000 inhabitants, covering periods of constant population size as well as putative periods of population bottlenecks with less than 4000 inhabitants due to severe epidemics. 19 Migration has been sparse, 18 and presumably the expansion has mainly been due to increased reproduction rates. The long distances between the villages, commercial monopoly, and legislation, imposed further isolation between different geographical areas on the Faroe Islands.…”